Lactose intolerance

The cause of the discomfort is a lactase deficiency. The lactase enzyme is responsible for splitting lactose in the small intestine. Only after having been split by lactase, the lactose constituents can be processed. If a lactase deficiency is present, the enzyme cannot be formed or only in insufficient amounts. Consequently, lactose may only be partially digested or not at all.

Since milk and dairy products cause the described discomfort, dietary recommendations chiefly focus on avoiding or reducing milk, dairy products and foods containing lactose.

Additionally, there is a range of atypical symptoms which vary individually in intensity and occurrence. These include headache, fatigue, sleep disorder and skin irritations.

There is a number of tests that are used to determine whether or not a patient is suffering from lactose intolerance:

Hydrogen breath test:
The hydrogen (H2) breath test is one of the easiest and safest methods to diagnose lactose intolerance. The patient is given a lactose solution to drink, whereupon the hydrogen content of the breath is measured. If the lactose was not split by the lactase enzyme, it is metabolised by enteric bacteria into hydrogen gas (H2), among others, which is then predominately released through the breath. The less tolerant a patient is to lactose, the greater the hydrogen content of the breath.

Lactose tolerance test:
The lactose tolerance test is usually combined with the hydrogen breath test. After the patient has drunk a lactose solution, blood samples are taken and examined in terms of an increased glucose level. The ingestion of lactose is generally followed by the enzymatic release of glucose, which then passes through the intestinal wall into the bloodstream, where it can be detected. If the lactase enzyme is missing, a correspondingly small amount of glucose enters the blood. When the glucose concentration is below 20 milligrams per decilitre, nutritionists regard this as evidence for lactose intolerance.

Gene test:
The gene test is still a relatively new diagnostic procedure. It provides insight into the genetic predisposition to lactose intolerance. Currently, this method is not yet a standard procedure, as it is very time-consuming and costly by comparison to others.

Foods with low lactose contents are usually well-tolerated when ingested in small amounts. In most cases, discomfort only occurs above 10 grams of lactose. In order to identify the tolerated amount of lactose, it is recommended to follow a lactose-free diet for a period of 4 to 6 weeks.
Once all symptoms are gone, various dairy products may be ingested, initially in small amounts. At the beginning, fermented dairy products, i.e. yoghurt, soured milk, kefir or hard cheese are particularly suitable. They are all characterised by good overall tolerability. Gradually, further products may then be tried while increasing the ingested amounts. In exceptional cases, the ferment may also be administered in the form of tablets (e.g. Lactrase).